Air-operated drill press attachment



Nov. 4, 1958 R. E. DOEDEN 2,858,716

- AIR-OPERATED DRILL PRESS ATTACHMENT Filed Oct. 5. 1955 United States Patent() Roland E. Doeden, Sherwood, Ohio, assignor to Doeden Tool Corp., Sherwood, Ohio, a corporation of Ohio Application OctoberS, 1955, Serial No. 538,604

2 Claims. (Cl. 77-33.S)

The present invention relates generally as indicated to an air-operated drill press attachment, and more particularly to a self-powered attachment which is characterized by the fact that the motivating uid as exhausted from the motor thereof is employed as a coolant and lubricant.

Heretofore, difliculty has been encountered in the drilling of small holes, such as, for example, holes of .070 diameter as through the corners of hexagon lock nuts or the like where the latter are to be wire-locked against loosening as is customary in the aircraft industry and elsewhere.

I have found that such small diameter holes can be drilled in aluminum and brass, for example, most expeditiously by employing a high-speed, self-contained, vibrationless power unit operating at, say, lifteen to twenty-live thousand R. P. M. and 'with a mist of coolant and lubricant instead of the customary flooding of the drill and work area with liquid coolant.

Accordingly, it is a primary object of this invention to provide an air motor operated, vibrationless, selfcontained power unit for drill press attachment which is capable of high speed rotation, as desired, and which is designed to lubricate and to cool the drill and work area by exhausting the motive iluid longitudinally along the drill to the work area, the motive uid having dispersed therein fine particles of oil to form a mist which is capable of absorbing great quantity of heat from the drill to maintain the same cool and at the same time prevent dulling of the cutting lipsvthereof.

It is another object of this invention to provide an attachment of the character indicated which is of simple` and compact form and arranged for coaxial mounting in the quill of a drill press, the *quill providing axial feed while rotation is provided by the air motor which is contained within the attachment and which has a drive shaft coaxial with'the housing of the attachment and with the quill.

Another object of this invention is to provide an attachment of the character indicated which is automatically started and stopped respectively during the downward and upward feed of the drill press quill, whereby all that the operator need do is to connect an air supply hose to the attachment and then operate the drill press quill feed mechanism.

Another object of this invention is to provide an attachment for economically converting slow-speed conventional drill presses, or motorless drill presses, or even old, discarded drill presses, into highly efhcientand useful high-speed drill presses.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed draw- 2 f ings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1A is a side elevation View, partly in cross-section, showing the present invention vmounted on a conventional drill press, a portion only of the quill and post of the drill press being shown; and

Fig. 2 is a transverse cross-section `view through the drill press post showing the actuating cam for the` drill press attachment.

Referring now in detail to the drawing, the reference numeral 1 designatesthe lower end 'portion of a drill press quill, and the referencey numeral 2 designates the drill press supporting post` which carries at its upper end the quill support mechanism (not shown) and which has vertically slidably adjustable therealong a work-supporting table (not shown).

The attachment herein housing 3, preferably machined from bar stock, to provide a tang `4 which ts into the lowerY end of the quill or quill adaptor 1 ofthe drill press and which tank 4 may be of any well-known form so that it is securely locked in place against rotation with respect to the quill.

The lower end of saidhousing 3is formed with a cylindrical cavity 5, and between the tang 4 and the upper end wall of the cavity 5, said housing 3 is formed with a cross-bore 3' in which a valve bushing 6 is press-fitted or otherwise secured in place.

Said valve bushing is provided with a seat at its inside corner rwith which the resilient seat ring carried by the reciprocable valve member as desired.

Threaded into the other end of the cross-bore 3 is a fitting 8 to which an air supply hose may be connected. A spring 9 compressed between Athe'valve member 7, and said lifting 8 normally urges the valve member 7 into engagement with the seat of bushing 6 so that air ow is prevented into the cavity v5.

The mechanism for'moving the valve member 7 to unseated position to permit flow of air from the inlet port and through the passage is here shown as comprising a cam`10 mounted on the drill press post 2 as by means of U-bolts 11 and clamping elements 12 thereof. Pivotally mounted to the housing 3 on the pin 14 is an `arm 15 which is adjustable in length and which is adapted to be swung counterclockwise by cam 10 as the quill 1 or spindle and housing 3 are moved downwardly.

Said arm 15 carries an adjustable screw 16, the head of which engages the valve member 7 to urge the latter inwardly to unseated position, in which position it is retained during continued downward movement of the quill 1 and housing 3. As the quill 1 and housing 3 move upwardly, the arm 15 will be permitted by the cam 10 to return to the position shown in Fig. l at which time the adjusting screw 16 has disengaged from the valve member 7 to permit the latter to be seated.

Closely tted into the cavity of the housing 3 is a self-contained air motor assembly 20, the stator of Patented Nov. 4, 1958 manner of mounting the shown comprises a cylindrical 7 is engaged or disengaged The rings 21 and 23 are closely fitted in the cavity so as to insure concentricity between the rotor shaft 22 and the quill 1; and, in order to make unnecessary the accurate rotary positioning of the air motor assembly in the housing 3, the-.upper end of the ring 21 is formed with an annular inlet recess 25 which registers with valve bushing 6 passages in all rotary positions of the motor assembly in cavity 5 and from which inlet passages 25A lead into the center stator part 24.

Theother ring 23 and the center stator part 24 are formed with peripheral exhaust slots 26 and, in addition, the center part will be provided with exhaust ports preferably in the lform of transverse slots 27 through the wall thereof.

For the purpose of. clamping said air motor assembly 20 in `place in the housing 3, there is provided a threaded thimble 28, said thimble also providing threads for the mounting of a -nozzle 29having an orice 30 at its end which is co-axial with the drill D.

A chuck body 31 is threaded onto the end of the rotor shaft 22 into the lower end of which a collet 32 lits, said collet being contracted lby turning the cap 34 (threaded on chuck body 31) which draws the nosepiece 35 upwardly.

Now when a lubricating unit 36 is installed in the air pressure supply line 37,the air which flows into the air motor 20 to rotate the'latter at a free speed of say 30,000 R. P. M. or a working speed under load of from l5.-25,000 R. P. M., the air will carry therewith a quantity of lubricant innely divided droplet form, whereupon the air which is exhausted from the motor 20 will pass through the exhaustslots 26, through the openings in the thimble 28, and through the annular space between the chuck assembly and the nozzle 29.

Finally, the lubricant-laden'air passes at high velocity through the orice whence it flows axially along the drill extracting heat therefrom and toward the work area. The cutting lipsof the drill D are thus lubricated and .cooled to prevent dulling thereof.

In the .drilling of brass and aluminum, for example, I have found that an air pressure of 90 p. s. i. will operate the air motor at the speeds indicated, and for ecient cooling and lubricating action ,the lubricant preferably is cutting oil which is introduced into the air stream in an amount from 20,-50 cubic inches per thousand cubic feet of free air. The lubricant-laden air, in addition, is an excellent lubricant for the sliding vanes inside the stator part 24.

From the foregoing description of the `operation of this air-operated drill press attachment, it is vevident that the starting and stopping of the drill rotation is automatic, the motor being started automatically during the downward movement of the quill 1 and housing 3 and ybeing automatically shut ott during the upward movement of said quill 1 and housing 3.

Thus, all that the operator need do is to mount this unit on any standard drill press, connect an air supply line 37 with a lubricator unit 36 therein to the fitting 8 of the attachment, mount a drill D in the air motor driven chuck, and operate the quill feed mechanism of the drill press.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or'the equivalent of such, be employed.

I therefore particularly point out and as my invention:

l. In combination, a drill press of the typehaving a post and a reciprocable quill; a generally cylindrical housing having one end formed for attachment to said quill, said housing being formed with a transverse bore adjacent such one end, with an inlet port for supplying fluid under pressure into such bore, and with a cylindrical cavity at the other end; a valve mechanism in such bore including a movable valve member adapted to be actuated from seated to unseated position to respectively prevent and permit ow of fluid from said inlet port into said cavity; a valve-actuating lever pivotally connected to said housing; a cam on said post operative, when said quill and housing are moved in one direction, to swing said lever to valve member unseating position; a fluid motor assembly removably tted into said cavity and having a rotating drive shaft to which a rotary tool is adapted to be secured for operating upon work thereadjacent; and a nozzle secured to said housing to cause exhausted fluid from said motor to ow along the rotary tool and toward the work being operated upon by the tool.

2. The combination of claim l wherein a uid supply line is connected to said inlet port and a lubricating unit is provided in said fluid supply line to introduce lubricant into the fluid whereby the lubricant-Huid mixture is effective not only to cool the tool but to lubricate distinctly claim References Cited in the file of this patent UNITED STATES PATENTS 2,674,098 Taylor Apr. 6, 1954 FOREIGN PATENTS 616,765 Great Britain Ian. 26, 1949 701,287 Great Britain Dec. 23, 1953 

